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Species introductions are among the most dramatic human-induced impacts on aquatic and terrestrial ecosystems around the world.
Stability patterns of an estuarine benthic community were investigated through guild interaction models representing the community
before and after human-mediated species invasions. The study area was Yaquina Bay, a developed estuary on the central Oregon
coast, U.S., where at least 12 species of nonindigenous invertebrates have been inadvertently introduced. Three of the introduced
species (the polychaetes Hobsonia florida and Pseudopolydora kempi and the cumacean Nippoleucon hinumensis) are probably among the 10 most abundant invertebrate species in the intertidal benthic community. To estimate effects and
potential risks of species introductions on the native community we constructed 2 types of community models based on functional-group
interactions, namely, activity guild models and trophic guild models. In both cases we observed that overall feedback has
a strong tendency towards zero in pre-invasion and post-invasion models. We generated 12,000 random models of similar size
and could not detect this tendency. We suggest that the weak or absent overall feedback in this community may be an ecological
property and not an intrinsic property of large systems as such. The reduced response to input from either invertebrate invasions
or removal of native top predators, may to some extent buffer the community from such impacts. Alternative guild models suggested
increased risk of stability decline in the invaded community even after accounting for potential complexity effects on stabllity.
Further species introductions in this intermediately invaded estuary should be avoided. 相似文献
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Castillo-Sandoval Isaí Fuentes-Cobas Luis E. Pérez-Cazares Bernardo E. Esparza-Ponce Hilda E. Fuentes-Montero María E. Castillo-Michel Hiram Eichert Diane Reyes-Cortes Ignacio Carreño-Márquez Iván J. Napoles-Duarte José M. Montero-Cabrera María E. 《Mineralogy and Petrology》2018,112(6):865-879
Mineralogy and Petrology - The Cave of Swords was discovered in 1910 at Naica, Chihuahua, México. During the last century, human presence has changed the microclimate conditions inside this... 相似文献
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Abstract— The Kirbyville meteorite is an equilibrated monomict eucrite with a mode (calculated in wt.%): plagioclase 37, inverted pigeonite 58, silica 3, ilmenite 1.4 and troilite 0.3. The pyroxene compositional range is Wo 2–42, Fs 27–62, En 30–40 with an average of Wo 7. The plagioclase average mean is An 89. Kirbyville is one of the “main group” eucrites. 相似文献
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